1. Field of the Invention
The present invention relates to an optical pickup apparatus and a manufacturing method of the optical pickup apparatus, and, more particularly, to an art of properly correcting coma aberration of each of a plurality of lenses incorporated in an optical pickup apparatus in a simple manufacturing/adjustment process.
2. Description of the Related Art
It is known that an objective lens, which is mounted on an optical pickup apparatus and is used for recording/reproduction for an optical disc compatible with the BD (Blu-ray Disc) standard, the HD-DVD (High Definition Digital Versatile Disc) standard, etc., has great coma aberration caused by deviation between an incidence plane top and an emitting plane top, irrespective of its material (made of glass, made of a resin, etc.). FIG. 12 exemplifies a relationship between an amount of deviation of the plane top and coma aberration in the objective lens, and as shown in this drawing, in the objective lens to be used for the BD standard in this example the coma aberration of 40 mλrms occurs with respect to the deviation of the plane top of 1 μm.
The WDs (Working Distances) of the objective lenses to be used for the optical pickup apparatus are not necessarily the same and varies with types of the optical discs, and for example, the optical pickup apparatus supporting both of the BD-standard optical disc and the CD/DVD-standard optical disc is required to provide two objective lenses, one for the BD standard disc and the other for the CD/DVD standard disc. In such a pickup apparatus, an optical axis adjustment should be performed to properly correct the coma aberration with respect to individual objective lenses at the time of manufacturing (see Japanese Laid-Open Patent Publication No. 2008-65889, for example).
In the art disclosed in the above publication, a holder for adjusting the optical axis is individually provided for each objective lens so as to properly correct the coma aberration of each objective lens. Therefore, the structure of the optical pickup apparatus becomes complicated when the art in the above publication is employed. In the case of employing the art in the above publication, the optical axis adjustment of each objective lens is required to be individually performed, and thus, it is inevitable that manufacturing/adjustment process of the optical pickup apparatus becomes complicated. The objective lens to be used for the recording/reproduction for the optical disc compatible with the BD standard, HD-DVD standard, etc., has greater coma aberration than that of the objective lens to be used for the recording/reproduction for the optical disc compatible with the DVD/CD standard, and thus, an accurate work is required at the time of manufacturing/adjustment, thereby increasing load of manufacturing.